Generally, when vehicles are traveling on a road with a speed bump, in a dented road, in an unpaved road, and the like, bottoms of the vehicles may be scraped or safety accidents may occur. Therefore, the vehicles include suspensions configured to smoothly pass the roads.
The suspensions of the vehicles, connected to axles of the vehicles, control vibrations or shocks received from the road surface during the traveling of the vehicles not to be directly transferred to the vehicles themselves, prevent vehicle bodies or passengers, cargos, and the like from being damaged, and improve ride comfort of the vehicles.
The suspension is configured of a chassis spring configured to cushion shocks from the road surface, a shock absorber configured to control free vibration of the chassis spring to improve ride comfort, a stabilizer bar configured to prevent rolling of the vehicle, and the like.
The shock absorber in the suspension is installed between the vehicle body and wheels, and absorbs natural vibration generated by shock received in a spring during the traveling of the vehicle to increase damping speed of the vibration and to improve the ride comfort.
Electronic control suspension system (ECS) in which the shock absorber and an air spring are mounted is used to control an actuator so that the vibration from the road surface is minimized to promote the improvement in the ride comfort.
However, since the ECS performs suspension and damping control at the point of time when the vehicle passes the speed bump, the damping for the vibration according to the road surface condition is insufficiently done. Further, since the drivers may not frequently recognize road conditions (speed bump, Belgian road, unpaved road, and the like), vibration damping of the vehicle is not easy.